This invention relates to valves and pressure regulators generally, and specifically to a fluid pressure regulator particularly suited for (but not limited to) use in agricultural irrigation systems.
It is well known to use pressure regulators in irrigation systems in order to provide substantially constant, regulated outlet pressure over a wide range of regulator inlet pressures, to thereby insure the supply of water is maintained at a substantially uniform pressure to a sprinkler or other irrigation device. The need for such regulators is particularly acute in low pressure systems because even slight variations in pressure along a system operating at low pressure causes much greater variations and discharges than the same system operating at high pressure.
The assignee of this invention currently manufactures and sells fluid pressure regulators of the flow-through type, having an inlet at one end of a tubular housing and an outlet at the other end of the tubular housing. A valve or regulator seat is fixed within the housing and is adapted to be engaged by a tubular plunger which is spring biased away from the seat (in the direction of fluid flow) so that under normal conditions, maximum flow through the regulator is permitted. In the event of a pressure surge, the plunger is moved by back pressure within a diaphragm chamber, against the action of an opposed coil spring (and against atmospheric pressure), toward the regulator seat to thereby decrease flow through the regulator until the pressure is reduced, at which point the plunger will stop or, if pressure decreases sufficiently, move upwardly away from the seat to thereby increase the flow. In this way, the plunger constantly seeks an equilibrium position within the regulator to maintain a substantially uniform outlet pressure.
It would be advantageous to incorporate a manual shut-off feature in pressure regulators as described above in order to, for example, facilitate repair/replacement of downstream sprinklers or other components, and/or to turn some sprinklers on and off at various times in a multi-sprinkler system in order to implement desired sprinkling patterns.